UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the

Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): May 23, 2017

Sterling Bancorp

(Exact name of registrant as specified in its charter)

Registrant’s telephone number, including area code: (845) 369-8040

Not Applicable

(Former name or former address, if changed since last report.)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§ 230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§ 240.12b-2 of this chapter). Emerging growth company ¨

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ¨

Item 5.03—Amendments to Articles of Incorporation or Bylaws; Change in Fiscal Year.

On May 23, 2017, the Board of Directors (the “Board”) of Sterling Bancorp (the “Company”), a Delaware corporation, amended and restated the Company’s Bylaws, effective immediately. The amended and restated Bylaws includes a new provision, Article II, Section 11, which provides the Board with the ability to appoint directors emeritus.

Item 9.01—Financial Statements and Exhibits

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.